For future reference for anyone needing a clutch a my '70 383 R/T turned out to be: steel bellhousing, 143 tooth flywheel, 11' clutch 23 spline one inch input, the same set up as a '69 Road Runner and a some other Mopars. from what I found ouit this is fairly common on the HP motors but for some reason the books don't list it.
I beleive all 23 spline inputs are 1"? if not throw another variable in there.